01 · Device purpose
Product Overview and Selection Scope
SN74LVC1G240 is one inverting line driver with an active-low output-enable input and a 3-state output.
- Wide supply range: 1.65 V to 5.5 V operation.
- Inverting path: with OE LOW, A HIGH produces Y LOW and A LOW produces Y HIGH.
- 3-state isolation: OE HIGH places Y in the high-impedance state.
- 5.5 V input acceptance: A and OE are specified from 0 V to 5.5 V.
- Output drive: ±24 mA at VCC = 3.0 V under the specified DC tests.
- Partial power-down: Ioff helps prevent damaging current backflow when the device is powered down.
Selection boundary: This is an inverting push-pull driver with a high-impedance disabled state. It is not a non-inverting buffer, open-drain output, analog switch or voltage regulator.
02 · Logic and pins
Active-Low Enable, Inverting Output and Pin Assignment
OE controls whether the output drives the inverted input or disconnects from the shared node. High impedance is an electrically released state, not a logic HIGH or logic LOW level.
| Pin | Name | Type | Function | Engineering note |
|---|---|---|---|---|
| 1 | OE | Input | Active-low output enable | LOW enables Y; HIGH places Y in high impedance. |
| 2 | A | Input | Data input | Y is the logical inverse of A while enabled. |
| 3 | GND | Power | Ground | Use a short local return path. |
| 4 | Y | Output | Inverting 3-state output | Check output loading, receiver thresholds and bus contention. |
| 5 | VCC | Power | Supply | Place local bypass capacitance close to pins 5 and 3. |
03 · Orderable options
Ordering Codes and Package Selection
| Ordering number | Temperature range | Package | Top marking | MSL | Packing |
|---|---|---|---|---|---|
| SN74LVC1G240DCKR | -40 °C to +125 °C | SC70-5 / SOT353 equivalent | CK5 | MSL 3 | Tape and reel, 3,000 units |
| SN74LVC1G240DBVR | -40 °C to +125 °C | SOT23-5 | C40R | MSL 3 | Tape and reel, 3,000 units |
Additional lot, date, vendor, logo or environmental markings may appear. Confirm the complete ordering code and package drawing during receiving inspection.
04 · Design envelope
Recommended Operating Conditions and Absolute Limits
| Parameter | Condition | Minimum | Maximum | Unit |
|---|---|---|---|---|
| Supply voltage, VCC | Operating | 1.65 | 5.5 | V |
| Supply voltage, VCC | Data retention only | 1.5 | - | V |
| Input voltage, VI | Operating | 0 | 5.5 | V |
| Output voltage, VO | Operating | 0 | VCC | V |
| Input transition, Δt/Δv | 1.8 V / 2.5 V supplies | - | 20 | ns/V |
| Input transition, Δt/Δv | 3.3 V / 5.0 V supplies | - | 10 / 5 | ns/V |
| Ambient temperature, TA | Operating | -40 | 125 | °C |
Input logic thresholds
| VCC range | VIH minimum | VIL maximum | Unit |
|---|---|---|---|
| 1.65 V to 1.95 V | 0.65 × VCC | 0.35 × VCC | V |
| 2.3 V to 2.7 V | 1.7 | 0.7 | V |
| 3.0 V to 3.6 V | 2.0 | 0.8 | V |
| 4.5 V to 5.5 V | 0.7 × VCC | 0.3 × VCC | V |
Absolute maximum and handling limits
| Parameter | Minimum | Maximum | Unit |
|---|---|---|---|
| Supply voltage, VCC | -0.5 | 6.5 | V |
| Input voltage, VI | -0.5 | 6.5 | V |
| Output voltage, high-impedance or power-off | -0.5 | 6.5 | V |
| Output voltage, HIGH or LOW state | -0.5 | VCC + 0.5 | V |
| Continuous output current | ±50 | mA | |
| Continuous VCC or GND current | ±100 | mA | |
| Junction / storage temperature | -65 | 150 | °C |
05 · Static performance
Output Levels, Leakage and Supply Current
| Parameter | Test condition | VCC | Limit or typical value | Unit |
|---|---|---|---|---|
| VOH | IOH = -100 µA | 1.65 V to 5.5 V | Minimum VCC - 0.1 V | V |
| VOH | IOH = -4 / -8 / -16 / -24 / -32 mA | 1.65 / 2.3 / 3.0 / 3.0 / 4.5 V | Minimum 1.2 / 1.9 / 2.4 / 2.3 / 3.8 V | V |
| VOL | IOL = 100 µA | 1.65 V to 5.5 V | Maximum 0.1 V | V |
| VOL | IOL = 4 / 8 / 16 / 24 / 32 mA | 1.65 / 2.3 / 3.0 / 3.0 / 4.5 V | Maximum 0.45 / 0.30 / 0.40 / 0.55 / 0.55 V | V |
| II | A or OE at 5.5 V or GND | 0 V to 5.5 V | ±0.1 µA typical; ±5 µA maximum full range | µA |
| Ioff | VI or VO = 5.5 V | 0 V | ±0.1 µA typical; ±10 µA maximum full range | µA |
| ICC | VI = 5.5 V or GND, IO = 0 | 1.65 V to 5.5 V | 0.1 µA typical; 10 µA maximum full range | µA |
| ΔICC | One input at VCC - 0.6 V | 3 V to 5.5 V | 500 µA maximum | µA |
| Ci | VI = VCC or GND | 3.3 V | 4 pF typical | pF |
06 · Dynamic performance
Propagation, Enable and Disable Timing
Switching values depend on supply and capacitive load. The supplied specification lists typical values over the -40 °C to +125 °C operating range.
| Parameter / path | 1.8 V | 2.5 V | 3.3 V | 5.0 V | Condition / unit |
|---|---|---|---|---|---|
| tpd, A to Y | 6.3 | 3.9 | 4.1 | 2.3 | Typical ns, CL = 15 pF |
| tpd, A to Y | 8.8 | 5.5 | 4.2 | 3.1 | Typical ns, CL = 30 pF or 50 pF |
| ten, OE to Y | 9.7 | 6.0 | 5.2 | 3.5 | Typical ns, CL = 30 pF or 50 pF |
| tdis, OE to Y | 7.6 | 4.5 | 4.6 | 3.2 | Typical ns, CL = 30 pF or 50 pF |
| Cpd, output enabled | 18 | 18 | 19 | 21 | Typical pF at 10 MHz, +25 °C |
| Cpd, output disabled | 2 | 2 | 2 | 4 | Typical pF at 10 MHz, +25 °C |
Timing interpretation: ten covers low- and high-level output enabling; tdis covers low- and high-level output disabling. Validate the receiver, PCB load, supply tolerance and bus turn-around interval in the finished design.
07 · Implementation
Power-Up, Bus Control and PCB Guidance
- Default to high impedance: tie OE to VCC through a pullup resistor when a disabled state is required during power up or power down; size the resistor for the current-sinking ability of the driving source.
- Do not leave inputs floating: hold A and OE at defined logic levels.
- Prevent contention: insert sufficient dead time when multiple 3-state drivers share one node.
- Interpret high impedance correctly: add an external pullup or pulldown only when the released bus needs a default logic level.
- Check powered-down paths: Ioff helps protect partial-power-down interfaces, but board-level back-power paths still require validation.
- Bypass locally: place a 0.1 µF capacitor close to VCC and GND and keep the high-current loop short.
System check: Validate output loading, receiver thresholds, enable/disable overlap, power sequencing, signal integrity, ESD protection and thermal conditions on the finished PCB.
08 · Mechanical
SOT23-5 and SC70-5 Packages, Land Patterns and Packing
The two packages share the same logical pin assignment but have different body dimensions, lead pitch, marking and thermal impedance. Do not share one PCB footprint between them.
| Dimension | SOT23-5 | SC70-5 | Unit |
|---|---|---|---|
| Overall height A | 1.050 to 1.250 | 0.900 to 1.100 | mm |
| Body length D | 2.820 to 3.020 | 2.000 to 2.200 | mm |
| Body width E | 1.500 to 1.700 | 1.150 to 1.350 | mm |
| Overall lead span E1 | 2.650 to 2.950 | 2.150 to 2.450 | mm |
| Lead pitch e | 0.950 BSC | 0.650 BSC | mm |
| Outer lead pitch e1 | 1.800 to 2.000 | 1.300 BSC | mm |
| Lead width b | 0.300 to 0.500 | 0.150 to 0.350 | mm |
| Lead length L | 0.300 to 0.600 | 0.260 to 0.460 | mm |
09 · Use contexts
Application Guidance and Design Limitations
The supplied specification lists the following application areas. These are use contexts, not end-product approvals or safety certifications.
AC ReceiversIsolate or invert compact control signals in appliance electronics.
Blu-ray and Home TheaterGate board-level control lines in audio and video systems.
Desktop and NotebookProvide local inversion and 3-state isolation in compact computing hardware.
Digital Video CamerasControl shared digital lines in space-constrained imaging hardware.
Mobile PhonesUse as a compact logic interface after power and loading checks.
GPS NavigationInvert or release digital control paths in navigation devices.
Portable Media PlayersImplement low-pin-count control gating in battery-powered media hardware.10 · Engineering answers
SN74LVC1G240 Engineering FAQs
What function does SN74LVC1G240 implement?
With OE LOW, Y is the inverse of A. With OE HIGH, Y enters the high-impedance state.
Is OE active HIGH or active LOW?
OE is active LOW. A LOW level enables the output; a HIGH level disables it.
Does high impedance mean logic HIGH?
No. High impedance means Y is electrically released. Use an external pull resistor if the shared node requires a defined idle level.
What supply range is recommended?
VCC is specified from 1.65 V to 5.5 V for operation.
How should OE be handled during power up or power down?
The PDF recommends tying OE to VCC through a pullup resistor when high impedance is required during power transitions. Size the resistor for the current-sinking ability of the source driving OE.
Can inputs accept 5.5 V when VCC is lower or off?
The recommended input range is 0 V to 5.5 V, and Ioff is specified for partial power-down. Validate all board-level back-power paths.
Which packages are listed?
SN74LVC1G240DBVR is SOT23-5 with C40R marking. SN74LVC1G240DCKR is SC70-5 with CK5 marking. Both are MSL 3 and tape-and-reel packed in quantities of 3,000.
Can an input be left open?
No. Every unused input must be held at VCC or GND.
This page summarizes the supplied SN74LVC1G240 Rev A.1 product specification for component evaluation. Confirm the current controlled specification, ordering code, marking, pin assignment, timing, package tolerances and qualification requirements before production release.
